Koula Kossiavelos graduated with a Bachelor of Laws degree from the University of Adelaide in 1980, followed by a Graduate Diploma in Community Languages from the University of South Australia in 1981. In 1982, she was a participating student at the University of Athens summer school organised by Temple University of Philadelphia law school. During her university studies, Kossiavelos was a founding member of a Greek youth and music radio program. In recognition of her commitment to fostering the Greek community and the development of a broader multicultural society, Kossiavelos was granted a Commonwealth Government Australian-Greek Presidential Award in 1982 [PM]. This scholarship enabled Kossiavelos to study the legal system of Greece as it related to the Australian community.

Kossiavelos served articles with the firm Johnston, Withers, McCusker and Co. In 1984 she joined Martirovs, Kadis & Metanomski as a solicitor; in 1986 she became a partner at the firm. It was here that she developed expertise in trial work and the conduct of civil law matters. In 1987 she represented Greek-Australian graduate students in raising money to support a Chair of Modern Greek at Flinders University [Flinders]. Between 1984 and 1989 she acted as honorary legal advisor to the Greek Orthodox Archdiocese of Australia and performed the voluntary role of duty solicitor at the Adelaide Magistrates' Court. She was a member of the Citizens' Advice Bureau and the Women's Legal Service. In addition, Kossiavelos volunteered as a legal adviser at Thebarton, Norwood and Parks Legal Service. She has been an Australian delegate to the International Conference of Greek Youth Abroad and President of the Greek Australian Graduates Association. She also contributed as an Executive Board member of the Alumni Association of the University of Adelaide.

Kossiavelos established herself as a sole practitioner in 1991; she practised in a wide range of civil cases, including personal injury claims, family law, criminal-injuries compensation claims, civil litigation, industrial law and defamation. During this time she was Legal Advisor and National President of the Pan-Arcadian Federation of Australia, and Australian delegate at the International Conference of Council of Hellenes Abroad in 2001 and 2003. From 2005 to 2006 Kossiavelos was the National Coordinator of the Australian Hellenic Council.
In 2007 Kossiavelos was appointed a Stipendiary Magistrate. The Attorney-General Michael Atkinson noted upon her appointment that Kossiavelos had "thrown [herself] into serving others" and that she had "also been a stalwart of Greek organisations and migrant women's groups" [Media Release].

Koula Kossiavelos has made a considerable contribution to the legal system in South Australia. She continues to support community and legal organisations, which provide services to migrant women in need, and to promote a multicultural society.

Sources used to compile this entry: Koula Kossiavelos interviewed by Kim Rubenstein in the Trailblazing Women and the Law oral history project, 2015, 6812025; National Library of Australia, Oral History and Folklore Collection; [Flinders] Ganzis, Nicholas, 'Politics and Greek Education in South Australia', In E. Close, M. Tsianikas and G. Frazis (eds) "Greek Research in Australia: Proceedings of the [3rd] Annual Conference of Greek Studies, Flinders University, 23-24 June 2000". Flinders University Department of Languages - Modern Greek: Adelaide, 115-144, https://dspace.flinders.edu.au/jspui/bitstream/2328/25587/1/Nicholas%20Ganzis%20.pdf (viewed 4 July 2016); [PM] 'First Australian-Greek Presidential Awards', PM Transcripts (Transcripts from the Prime Ministers of Australia), Transcript 5916, 24 September 1982, http://pmtranscripts.dpmc.gov.au/release/transcript-5916 (viewed 4 July 2016); [Media Release] 'New Magistrates Appointed', Mike Rann, Premier of South Australia, 29 March 2007, http://pandora.nla.gov.au/pan/86202/20081007-1101/www.premier.sa.gov.au/news20bc.html (viewed 7 July 2016).